1. Field of the Invention
The present invention relates to an arrangement structure of segments of offset fins in an exhaust gas heat exchanger for performing a heat exchange between exhaust gas generated by a combustion and a cooling fluid such as cooling water. The present invention is suitably applied to an EGR cooler for cooling exhaust gas in an exhaust gas recirculation system (i.e., EGR system).
2. Description of Related Art
For effectively reducing nitrogen oxide contained in exhaust gas generated by a combustion, exhaust gas used for an exhaust gas recirculation (hereinafter, referred to as "EGR") is cooled by an EGR cooler. However, when a heat exchanger having inner fins within a tube is simply applied to the EGR cooler, heat-exchanging capacity of the EGR cooler is difficult to be increased, because dust such as carbon is contained in the exhaust gas and is readily collected within tube, for example.